package com.gis.servlet;

import java.io.File;
import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import com.gis.util.Constant;
import com.gis.util.ResponseUtil;
import com.gis.util.RestResponse;
import com.gis.util.ResultCode;

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.io.FileUtil;

@WebServlet("/fileUpload")
public class FileUploadServlet extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	// 上传配置
	private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3; // 3MB
	private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB
	private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		// TODO Auto-generated method stub
		this.doPost(req, resp);
	}

	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// 检测是否为多媒体上传
		if (!ServletFileUpload.isMultipartContent(request)) {
			// 如果不是则停止
			ResponseUtil.writeJson(response, RestResponse.fail("Error: 表单必须包含 enctype=multipart/form-data"));
			return;
		}

		// 配置上传参数
		DiskFileItemFactory factory = new DiskFileItemFactory();
		// 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中
		factory.setSizeThreshold(MEMORY_THRESHOLD);
		// 设置临时存储目录
		factory.setRepository(new File(System.getProperty("java.io.tmpdir")));

		ServletFileUpload upload = new ServletFileUpload(factory);

		// 设置最大文件上传值
		upload.setFileSizeMax(MAX_FILE_SIZE);

		// 设置最大请求值 (包含文件和表单数据)
		upload.setSizeMax(MAX_REQUEST_SIZE);

		// 中文处理
		upload.setHeaderEncoding("UTF-8");

		// 构造临时路径来存储上传的文件
		// 这个路径相对当前应用的目录
		String uploadPath = Constant.UPLOAD_DIRECTORY;

		try {
			// 解析请求的内容提取文件数据
			@SuppressWarnings("unchecked")
			List<FileItem> formItems = upload.parseRequest(request);

			if (formItems != null && formItems.size() > 0) {
				// 迭代表单数据
				for (FileItem item : formItems) {
					// 处理不在表单中的字段, 就是文件
					if (!item.isFormField()) {
						// 生成时间戳文件前缀
						String now = DateUtil.now().replace(" ", "").replace(":", "").replace("-", "");
						String fileName = now + "_" + item.getName();
						// 创建文件
						File storeFile = FileUtil.touch(uploadPath + File.separator + fileName);
						// 保存文件到硬盘
						item.write(storeFile);
						ResponseUtil.writeJson(response, RestResponse.success(Constant.UPLOAD_SUCCESS, fileName));
						return;
					}
				}
			}
		} catch (Exception ex) {
			ResponseUtil.writeJson(response, RestResponse.fail(ResultCode.FAIL, ex.getMessage()));
			return;
		}
		ResponseUtil.writeJson(response, RestResponse.fail(Constant.UPLOAD_FAILED));

	}

}
